The invention relates generally to the area of removing contaminants from gas and air and more particularly to a wet type gas scrubber for removing particulate, solid materials from dirty air and gas, including a settling and clarifier tank.
Those skilled in the art are well aware that many types of wet scrubbers are available including scrubbers of the type in which a stream of flue gas is intimately contacted with a suitable scrubbing liquid for the purpose of removing particulate solids. Many of the drawbacks and disadvantages of prior art devices reside in their complexity. Because of the amount of pollutant material which a scrubber unit may have to handle, it can be easily clogged or slurry damaged. More specifically, sprays may become clogged and pumps, where they may be employed, become so fouled with the flow of pollutant material such as ash and soot that almost constant attention to the scrubber unit is required if it is to function properly. The treatment of dirty gases by wet scrubbers is ordinarily efficient in effecting the removal of the entrained solids from the gas, but some of the scrubbing liquid will, in turn, become entrained in the gas and will be carried out of the scrubber by the gas stream. This results in the loss of scrubbing liquid but also has other undesirable consequences arising from the presence of scrubbing liquid in the gas stream. Additionally, in wet scrubbers, the scrubbing liquid in the long run becomes super saturated with particulate matter, cutting down on the efficiency of the unit, and at the same time, easily fouling the scrubber internally as pointed out above. Wet scrubbers combined with clarifiers or other various forms of solid removal equipment are known. Efficient performance of such a unit is hindered by the amount of deposits of particulate solids which build-up on the interior surfaces of the unit tending to plug venturi sections or restricted clearance areas. Obviously, this cuts down on the flow of gas and fluids through the unit. Many wet scrubbers utilize concentric inlet and outlet chambers with the flue gas passing through the outer chamber, coming in contact with the scrubbing liquid, and then leaving the unit through the inner chamber. Units that utilize the outer chamber as their point of entry tend to become large as the cubic feed per minute increases, while units that utilize the inner chamber as their point of entry remain relatively small even with volume increases.
Among the references which may be considered in conjunction with this application are the following U.S. patents: U.S. Pat. Nos. 2,496,281; 2,259,030; 2,271,642; 2,551,890; 2,604,185; 2,792,905; 1,980,522; and 3,918,940.